1. Field
Embodiments of the present invention relate to a failure detecting method for a steering angle sensor that detects a turning angle, turning direction and central position of a steering wheel of a vehicle.
2. Description of the Related Art
Generally, a plurality of slits are provided, at regular intervals, at a rotary disc operatively connected to a steering wheel such that the rotary disc rotates when the steering wheel is turned to detect a turning angle and turning direction of the steering wheel. A steering angle sensor is disposed adjacent to a position corresponding to the slits to detect whether light has passed through the slits and to count how many times the light has passed through the slits using two photo couplers to output pulse signals having the same waveform and different phases during manipulation of the steering wheel, thereby detecting the turning angle and turning direction of the steering wheel.
Since the steering wheel makes two or three left and right turns, a central position detecting slit is also provided at the rotary disc to detect a central position of the steering wheel. The steering angle sensor is disposed adjacent to a position corresponding to the central position detecting slit to determine whether light has passed through the slit using a third photo coupler to output a pulse signal during manipulation of the steering wheel, thereby detecting the central position of the steering wheel.
If any one of the three pulse signals output from the steering angle sensor has failed with the result that no pulse is generated, however, the vehicle may not be stably traveled due to incorrect steering angle information.